Organocatalytic and electrophilic approach to oxindoles with C3-quaternary stereocenters.

A Lewis base-catalyzed asymmetric allylic alkylation of Morita-Baylis-Hillman carbonates derived from isatins has been investigated, which provides an electrophilic pathway to access oxindoles bearing C3-quaternary stereocenters. Excellent diastereoselectivity and high enantioselectivity have been obtained in the vinylogous functionalization of α,α-dicyanoolefin nucleophiles, giving multifunctional products with vicinal quaternary and tertiary chiral carbon centers.